1. Field of the Invention
The present invention relates to an X-ray mapping device for detecting X-rays and investigating elemental distribution.
2. Description of Related Art
In a first method of the related art, a noted element and an X-ray energy region for calculating X-ray intensity of the noted element are designated in advance, information for the measured location and the X-ray intensity acquired from the measured spectra is accumulated, and distribution analysis is carried out using X-ray intensity magnitude information.
In a second method, X-ray spectra for all measurement points are saved, and analysis is performed after measurement using X-ray spectra.
However, in the first analysis method, when elements are present within the sample for which elements have not been estimated in advance, there is the substantial drawback that information regarding the presence and distribution of this element has to be disregarded.
In the second method, all of the information resources are filled up to a maximum in order to save all of the measured spectra and there is the disadvantage that an extremely long time is required in order to analyze all of the spectra after measurement.
It is therefore the object of the present invention to provide data for X-ray mapping analysis in such a manner that regions of the sample that contain different elements and regions where the concentration of contained materials is different are automatically split up into different groups so as to enable detailed analysis immediately after measurement.
The present invention adopts the following means in order to resolve the aforementioned problems.
An X-ray mapping analysis method for putting typical spectra existing in a sample into a database employs an X-ray mapping device comprising: excitation means for irradiating a sample with a primary beam in order to excite X-rays; primary beam control means for controlling the beam from front to back and from left to right with respect to the sample; X-ray detecting means for measuring X-ray intensity while discriminating energy of X-rays from the sample; spectra comparison means for comparing two X-ray spectra obtained by the X-ray detecting means; and a spectra database capable of registering X-ray spectra during measurement, and the method comprises the steps of: starting measurement with the spectra database empty; irradiating a designated location within the sample with a primary beam using the primary beam control means; irradiating the sample with the primary beam for a fixed period of time in order to acquire a measurement spectrum; comparing the X-ray spectrum obtained through measurement and X-ray spectra in the spectra database using the X-ray comparison means; adding the X-ray spectrum obtained through measurement to the database when no matching X-ray spectra exists in the database; and repeating measurement at a designated measurement point.
In this X-ray mapping analysis method, numbers are assigned to X-ray spectra within the database, results determined by the comparison means are saved as database numbers, and analysis results are displayed using database number information and measurement position information so that distribution of elements can be confirmed visually.
With this mapping analysis method, X-ray spectra of little variation are obtained by performing measurements again for a long period of time at the same location and storing spectra acquired at such times in the database when no matching X-ray spectra exist within the database.
In a first method for the spectra comparison means of the X-ray mapping analysis method, the spectra comparison means designates a noted element and an X-ray energy region for calculating X-ray intensity of the noted element in advance, compares X-ray intensity of each element of the X-ray spectra in the database and the X-ray intensity of each element in the measured spectra, and determines spectra to be different when change is in excess of or equal to a reference.
In a second method for the spectra comparison means of the X-ray mapping analysis method, the spectra comparison means designates a noted element and an X-ray energy region for calculating X-ray intensity of the noted element in advance, calculates an intensity ratio of a total value of X-ray intensity of a noted element and an X-ray intensity for each element for the X-ray spectra in the database, and, for the measured spectra, calculates a ratio of the total value of X-ray intensity of the noted element and the X-ray intensity of each element, compares the intensity ratio for the same element, and determines that spectra are different spectra when change is equal to or in excess of a reference value.
In a third method for spectra comparison means for an X-ray mapping analysis method, an X-ray mapping device is characterized by spectra comparison means enumerating energy existing at peaks of X-ray spectra of the data base and of measured spectra and determining different spectra using the presence or absence of each peak.
In this X-ray mapping analysis method, the primary beam is an X-ray beam.